Safety switch construction



June 27, 1933.

H. J. HAMMERLY SAFETY SWITCH CONSTRUCTION Filed Nov. 19 1932 3 Sheets-Sheet l INVENTOR 47 HERMAI J. HAM Y,

June 27, 1933. J AMMERLY 1,915,992

SAFETY swmcn CONSTRUCTION Filed Nov. 19, 1932 3 Sheets-Sheet 2 Fig. .3- mm INVENTOR HERMAN J. HAMMERLY,

June 27, 1933. H. .1. HAMMERLY SAFETY SWITCH CONSTRUCTION Filed'Nov. 19, 1932 5 Sheets-Sheet 5 INVENTOR HA MERLY,

HERMAN J Patented June 27, -1933 UNITED STATES PATENT OFFICE HERMAN J. HAMMECRLY, NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE TRUE- IBULL ELECTRIC MANUFACTURING COMPANY, OF PLAINVI LLE, CONNECTICUT, A

CORPORATION OF CONNECTICUT sA'rETY swrrcn oonsrnncrron Application filed November 19, 1932. Serial No. M3318.

My invention relates to enclosed electric switches and more particularly to the type known as front-operated, rear-connected panel board switches, altho certain features are adapted to other types of switches.

One object of my invention is to prov.de a switch construction in which, when the switch is moved to off position, the operating handle is automatically moved to a position where its path of closing movement is blocked or intercepted by a substantial shoulder. in such a manner that it cannot accidentally be moved to closed or on position and in such a manner that, in order to m ve the handle to on position, a special preliminary manual shifting movement of the handle in a different direction is required.

Another object is to provide a front operated switch construction in which the operating handle is mounted on and movable with the door and is readily attachable to or detachable from the switch operating mechanism.

Another object is to provide an interlocking relation between the handle and the switch mechanism whereby the door cannot be opened until the switch has first been moved to the fully off position.

Anotherobject is to provide a construction in which the cover cannot be closed while the operating handle is in the on position.

Another object is to provide an enclosed switch construction in which the switch operating mechanism may be manually set so it cannot be engaged for operating movement'by the operating handle when the door is closed.

Another object is to provide an interlocking switch construction in which a single seal or locking means maybe employed to prevent access to either the fuses or to the switch parts and to prevent operable movement of the handle.

Another object is to provide a dead-front, back connected enclosed switch construction which may be assembled as a complete switch unit and which may be readily mounted upon the front plate of a panel beard construction by merely cutting out an opening the size of the switch box in the plate and securing the switch unit in position by screws operable from the front of the panel board.

Various advantages will be understood from the following specification.

Fig. 1 is a perspective view of a single switch unit with a supporting panel.

Flg. 2 is a plan and section showing the method of supporting the switch unit in a panel.

' Fig. 3 is a front view of a switch unit with a door open, one corner of the box being broken away to show the interior.

Fig. A is a horizontal section on the plane of the line H in Fig. 3 looking upwardly.

Fig. 5 is a fragmentary section on a larger scale showing parts of the switch operating mechanism;

Fi 6 is a vertical section and side elevation showing the parts oi the switch in the open circuit osition. I

Fig. shows the actuating mechanism in the closed circuit or on position.

Fig. 8 is a vertical section showing the part of the actuating mechanism in the open cir cuit position but disabled so that it cannot be actuated by the handle.

Fig. 9 is a perspective view of a detail of the connection between the handle and the actuating mechanism.

The box 10 may be of any suitable construction and has a face plate 11 secured to it in any suitable manner and extending laterally therefrom. The door 12 is hinged at j 13 to the face plate so as to swing ona' vertical axis when the switch is installed in the usual manner. lhese switches are adapted to be supported in panel boards such as 14 in which they are secured by means, for instance, of screws 15. X I

The, conducting parts of the switch may be of any suitable character supported for instance by an insulating block 16 as set forth in my application Serial Number 627,692 filed August 6th, 1932. External circuit terminals 17 project from the rear of the box. The block 16 also carries a number of fuse terminals 18 connected to the switch terminals in any suitable manner but preferably located in front so that the are readily accessible for attachment of the fuses 19.

The lower end-of the fuses are mounted in holders'or terminals 20 mounted on an insulating block 21 and provided with external circuit terminals 22.

The movable switch member 25 slides ver-' tically' in the insulating block 16 and is operated by a crank shaft 26 which is suitably supported in bearings located in or adjacent opposite sides 0 the box.

The quick make and break mechanism includes an oscillating disk 27 having lugs 28 agafitedto'engage the arm 29 of the crank s a This disc 27 also has an arm 31 hinged to the rod 32 on which is mounted the throwing spring 33. -The disc 27 has a lost motion connection with the disc 34 as is common in mechanism of this character and is hinged to a link'35. This link is also hinged to the arm 36 which in turn is hinged to pin 37 in one side of the box. A pin 38 serves as a stop for the arm 36 in one direction. A socket 39 is carriedby the joint between the arm 36 and the link 35, which socket is adapted to receive the offset end 40 of the countershaft 41 which is supported in bearings 42 carried by the door 12. The ofiset end of the counter-shaft 41 is detachably secured to the handle 43 which projects forwardly from the front of the door.

It will be seen that the counter-shaft 41 is rotatable in the bearings 42 and. also longitudinally movable, being normally held in the position shown in Figures 3, 4 and 5 by the action of the spring 44.

Attached to the door 12 is an interlocking member which provides a pocket and guide for the handle. This interlocking member consists of a plate 45 secured to the door and having arecess which is L shaped in cross section for controlling the movement of the handle. This recess is formed by a flange 46 on one side and the flanges 47 and 48 connected by the shoulder 49 on the other side. The back of the recess is closed by a wall 50. Y

When the parts are in the open circuit or off position corresponding to the position of the parts shown in Figures 1, 3, 4, 5 and 6 the counter-shaft 41 is held by the spring 44 is such a position that the handle is pressed against the wall 48 and held confined between .the lower edge of the plate 45 and the shoulder 49 so that it is impossible to raise. the

handle and operate the switch.

.To operate the switch therefore it is necessary first to push the handle toward the right as viewed in Figure 1 so as to free it from the shoulder49 and engage the offset crank p0rtion'40 in the socket 39 of the link motion. Thereupon the handle may be pushed upwardly, thus rotating the counter-shaft 41 and pushing the link 35 to the rear so as to close the circuit with a snap action through the quick make and quick break mechanism.

The handle will then remain in the raised position with the circuit closed and the handle may be locked in this position in any suitable manner if desired.

To open-the circuit it is, of course, only necessary to pullthe handle down from the position shown in Figure 7 whereupon the switch is opened with the snap action in the usual manner. As soon as the handle is released the spring44 forces the counter-shaft toward the left and the handle is again blocked beneath the shoulder 49.

From the foregoing it willbe seen that when the switch is open there is no connection between the operating handle and the snap action mechanism'because the crank in 40 is disconnected from the socket 39. 'Fhe door'may then be freely opened unless controlled by some further locking device. When the switch isclosed, however, the counter-shaft is interlocked with the socket 39 of the link motion and the handle 43 is held between the flanges 46 and 47 sothat it is impossible to open the door.

When the switch is open and the door, is open the socket member 39 ma be pushed rearwardly about the pivot pm 37. This would bring the socket 39 in a position where it could not be engaged by the crank pin 40. In this way the switch-can be completely disabled when in the open circuit position. The position of the parts would, in this disabled condition, be as illustrated in Figure 8.

In addition to the interlocking mechanism thus far described I-prefer to provide a spring pressed latch bolt 52 which is mounted in a housing 53 secured to the inside of the door and adapted to be operated by a fin er-piece 54 which is hinged to the pin 55 in t e hous- Y the fuses are readily accessible for inspection 7 and replacement. It is also impossible to close the circuit through the switch when the door is open because all of the hand actuating mechanism is carried by the door which of course has been displaced in opening the box.

When the door is closed it is automatically latched by the bolt 52 butthe operating handle of the switch is still held b the spring 44 in a locked position beneath t e shoulder 49. To close the circuit throu h the switch it is thereforemecessary to r orm two conscious acts, namely, slide t e handle to the right and then raise it deliberately until the snap action mechanism operates to closethe circuit. The door is then held closed by the action of the interior mechanism and cannot be opened until the handle is pulled down and the switch opened with the'snap action.-

The switch can then be disabled if desired by opening the door and pushing the socket 39 back to the position s own 1n Figure 8 so as to block the subsequent sliding eration may be provided, if desired.

I claim:

1. Enclosed switch mechanism including a box with quick-make and break mechanism, a door hinged to the box, an operating handle hinged to the door, a cran r shaft carried by the door and connected to the handle, said crank shaft being rotatable and slidable longitudinally for actuating the switch mechanism. I

2. A safety switchdncluding a box, switch actuating mechanism mounted in the box and including a link having a displaceable socket, a door for the box, a handle and counter-shaft carried by the door, said shaft having an offset portion adapted to engage in the socket for actuating the switch, said socket being'adapted to be displaced with respect to the counter-shaft for disabling the switch.

3. A safety switch including a box, switch actuating mechanism mounted in the box and including a link havin a displaceable socket, a movable door for the box, a handle and counter-crank-shaft carried by the door, saidshaft having an offset portion adapted to engage the soc et'for actuating the switch, said socket being adapted to be displaced with respect to the counter-shaft to block the movement thereof.

4. Enclosed switch mechanism including a box with quick-make and break mechanism, a door hinged to the box, an operating handle having a crank shaft carried by the door, said crank shaft being rotatable and slidable longitudinally for actuating the switch mechanism, said mechanism having a displaceable member engaged by said shaft when the shaft is moved longitudinally.

5. A safety switch construction including a box having a hin ed door, switch mechanism in the box, a andle havin a hinged and sliding connection with the oor, means of connection between the handle and the switch mechanism for actuating the same and means for compelling a lateral slidin movement of the handle before permittmg the hinged motion.

6. Switch mechanism including a box with quick-make and break mechan1sm,a door hinged to the box, an operating handle hinged to the door, a crank shaft carried by the door and connected to the handle, said crank shaft being rotatable and slidable longitudinally for actuating the switch mechanism and means for compelling the handle and shaft to be moved longitudinally before it can be rotated about the axis of the shaft.

7. A switch including a box, switch actuating mechanism mounted in the box and including a member having a displaceable socket, a door hinged to the box, a handle and counter-shaft carried by the door, said shaft being rotatable and slidable laterally in the door and having a portion adapted to said socket being adapted to be displaced with respectto the counter-shaft for disabling the switch.

8. Switch mechanism including a box, a door hinged to the box, an operating handle having a crank shaft carried by the door, said crank shaft being rotatable and slidable longitudinally for actuating the switch mechanism, said mechanism having a hinged member engaged by said shaft when the shaft is moved longitudinally.

9. A switch including a box, switch actuatin mechanism mounted in the box and including a swinging link having a displaceengage in the socket for actuating the switch,

able socket, a door hinged to the box, a handle and counter-shaft carried by the door, said shaft having an offset portion adapted to engage the socket for actuating the switch, said socket being adapted to be displaced with respect to the counter-shaft.

10. A safety switch construction including a box having a hinged door, switch mechanism in the box, a handle havin a hinged and sliding connection with the oor, crank and socket means of connection between the handle and the switch mechanism for actuating the same and means for compellin a lateral sliding movement of the handle hefore permitting the axial motion.

HERMAN J. HAMMERLY. 

